Method for recovering copper base metal from copper base ashes and residues

ABSTRACT

Copper base aggregates are washed with water to remove dust, are ball milled to separate oxides by shock, are screened to remove lumps for reprocessing and are cleaned by flowing with water over a vibrating table, to produce an intermediate copper base product for remelting.

United States Patent [72] Inventor Irving Bond Newton Highlands, Mass.[21 Appl. No. 852,554 [22] Filed Aug. 25, I969 [45] Patented Dec. 7,1971 [7 3] Assignee Bay State Smelting Co., Inc.

Somerville, Mass.

[54] METHOD FOR RECOVERING COPPER BASE METAL FROM COPPER BASE ASHES ANDRESIDUES 1 Claim, 1 Drawing Fig.

[52] US. Cl 241/21, 241/24, 241/30 [51] Int. Cl ..B02c 21/00, 1302c17/10 [50] Field of Search 24l/I5, 20, 2 I 24, 30, 8O

[56] References Cited UNITED STATES PATENTS 2,072,063 2/1937 Alton24l/80 UX 2,675,966 4/1954 Kihlstedt 241/20 3,086,718 4/1963 Lukas241/24 Primary E.\'aminerDonald G. Kelly AllameyMorse, Altman & OatesABSTRACT: Copper base aggregates are washed with water to remove dust.are ball milled to separate oxides by shock, are screened to removelumps for reprocessing and are cleaned by flowing with water over avibrating table, to produce an intermediate copper base product forremelting.

l NVE NTO R BY ATTORN EYS c DQ000000 PATENTEU DEB 715m METHOD FORRECOVERJING COPPER BASE METAL IFROM COPPER BASE ASHES AND RESIDUESBACKGROUND AND SUMMARY The present invention relates to the recovery ofcopper base metal from copper base aggregates, particularly copper baseashes and residues from other copper base metal production andfabrication processes and more particularly to such recovery in anefficaciously and economically. Difficulties have been encounteredparticularly in removing oxygen economically in order to leave a copperbase intermediate product useful as a copper melt or copper meltadditive.

The primary object of the present invention is to provide a process anda device for providing such an intermediate copper base product bywashing with water to remove dust, ball milling to separate oxides byshock, screening to remove lumps for reprocessing, and cleaning byflowing with water over a vibrating table. It has been found that, underthe contemplated circumstances, it is more economical to dispose of theoxides separated in'the foregoing manner than to attempt to recoveruseful copper base materials from the oxides by various techniques.

Other objects of the present invention will in part be obvious and willin part appear hereinafter.

The invention accordingly comprises the process and device, togetherwith their steps, parts and interrelationships, which are exemplified inthe present disclosure, the scope of which will be indicated in theappended claims.

BRIEF DESCRIPTION OF DRAWING For a fuller understanding of the natureand objects of the present invention, reference is made to the followingdetailed specification, taken in connection with the accompanyingdrawing which is a diagrammatic view of an apparatus embodying thepresent invention.

DETAILED DESCRIPTION With reference to the drawing, the startingmaterial is copper base ashes and residues 10, commonly called grisley,which is supplied to a well 12 through a coarse screen 14. Generally thecopper base ashes are composed of one or more of a member of the classconsisting of brass, cupronickel and bronze, containing at least 40percent copper and a remainder of other constituents.

This starting material is elevated to a chute 14 by a vertical bucketconveyor 16, which has driven pulley wheels 18, 20 for controlling anendless belt 22 having a series of bucket scoops 24. The lower extremityof conveyor 16 projects into well 12 so that bucket scoops 24continuously 16 projects the starting material to chute 14.

The starting material from conveyor 16 is guided by chute 14 to arotating drum 28, which, in conjunction with steel balls 30, constitutesa mill. Drum 28 is joumaled at bearings 32, 34 for rotation about anaxis, at the opposite ends of which are an inlet 36 and an outlet 38. Astream of water, introduced at 40, flows through inlet 36 to form a poolof water 42 in mill 28, and through outlet 38, which is associated witha series of screens to be described below. Generally the volume occupiedby steel balls 30 ranges from one-third to one-half the volume of drum28. Steel balls 30 range in diameter from 1.5 to inches.

Outlet 38 communicates with a series of a vertical screen 44 and aninclined screen 46. Screen 44, which is located in outlet 38 and ischaracterized by l to 2 inch openings, retains the copper base materialwithin the mill for a sufficiently long ing articles tend to beretainedb the rifiles in such a way as to ow transversely along the ries for capture m a suitable container 54 and the lighter oxidizedparticles flow transversely of the riffles in the direction ofinclination of the vibrating table for capture in a suitable container56.

OPERATION AND CONCLUSION In the process of the present invention, in oneexample, screen 46 has openings that are 1% inch in diameter and screen46 has openings that are one-eighth inch in diameter. Agglomerates fromwell 12 are transferred to chute 14 by conveyor 16 and immersed in asteady flow of water through inlet 40. Within mill 28, which rotatescontinuously, the agglomerates are impacted by steel balls 30 and theslurry produced by water 42 is flowed toward screen 38, which retainsballs 30 and the larger agglomerates and transmits that portion of theslurry containing particles less than IVs inch in diameter. This portionof the slurry flows over inclined screen 46, which transmits thatportion of the slurry containing the smaller particles and guides thatportion of the slurry contain ing the larger particles. The largerparticles, which are at least one-eighth inch in diameter, are caught bycontainer 50. The smaller particles, which are less than one-eighth inchin diameter, are flowed onto inclined vibrating table 48, where themetal bearing particles are caught in container 54 and the residue iscaught in container 56. Containers 50, 54 and 56 all have loweropenings, through which water escapes. Since certain changes may be madein the foregoing disclosure without departing from the scope hereof itis intended that all matter contained in the foregoing description andshown in the accompanying drawing be interpreted in an illustrative andnot in a limiting sense.

What is claimed is:

l. A process for recovering copper base metal from copper baseaggregates, said process comprising the steps of washing said aggregateswith water to remove dust, ball milling said aggregates in an aqueousslurry to separate oxides by shock, screening said aqueous slurry toremove lumps for reprocessing, screening to separate a slurry componentcontaining larger particles and a slurry component containing smallerparticles, and flowing said slurry component containing smallerparticles over a riffled vibrating support to separate metal bearingparticles from oxidized residue, said copper base metal being selectedfrom the class consisting of brass, cupronickel and bronze, said ballmilling being effected with steel balls that range in diameter from 1.5to 5 inches in a rotating mill having an axis, an inlet at one end ofsaid axis receiving said copper base aggregates, an outlet at the otherend of said axis discharging a slurry formed in said rotating mill, saidaxis being slightly inclined from said inlet to said outlet, saidscreening being effected by a first screen at said outlet for retainingpredeterminedly large particles in said mill and a second inclinedscreen at said outlet for receiving a flow of slurry from said outlet inorder to separate finer particles from coarser particles, the volume ofsaid steel balls ranging from one-third to one-half the volume of saidrotating mill, said screening including obstructing at said outlet witha screen having openings ranging from 1 to 2 inches.

